The role of adenyl cyclase in synaptic transmission will be studied in rabbit, rat and guinea pig sympathtic ganglia. Both chemical and electrophysiological assessments will be made of the effects of dopamine and other transmitter substances on the adenyl cyclase system. Intracellular recording systems will be used to determine the inhibitory effect of dopamine and methacholine on ganglionic transmission and to correlate such effects with changes, if any, in ganglionic adenyl cyclase activity.